TUCSON - A man who has been called "The World's Most Wanted Drug Kingpin", Joaquín "El Chapo" Guzmán Loéra, the head of Mexico's Sinaloa cartel, was arrested in Mexico, Saturday morning, reported The Associated Press.

Federal law enforcement agents in Arizona said they were deeply satisfied with news of the arrest Saturday morning. Several compared Guzmán's arrest to the manhunt and killing of al-Qaeda leader, Osama bin Laden.

But they're also concerned about the Sinaloa Cartel's infrastructure left in place along the Arizona-Sonora border, in cities like Agua Prieta, Nogales, and within Tucson itself.

"I'm not sure there's been a transition leader for the Sinaloa Cartel established," said a Homeland Security Investigations agent who spoke on condition of anonymity because he is not permitted to speak to the news media. If the cartel, which owns vast amounts of marijuana stash houses, money laundering networks and smuggling routes in Southern Arizona, does not have a transition in place, he worries another cartel will set to establish itself here and that could lead to the levels of violence that threatened to destabilize Mexico between 2008 and 2012.

During those years, the Beltrán Leyva family led by the now-deceased Arturo Beltrán, broke away from the Sinaloa Cartel and allied itself to the Zetas from Tamaulipas. The ultra-violent partnership shattered old peace accords and led to upwards of 50,000 killings over a five year period in Mexico. At the same time, the Juárez Cartel under the Carrillo Fuentes family warred with the Sinaloa Cartel, turning the city of Ciudád Juárez into the most murder capital of the world.

"We'll see the Carrillo Fuentes and the Beltrán Leyvas try to move into these areas," said Anthony Coulson, the retired agent in charge of the Drug Enforcement Administration's Tucson office.

An Alcohol, Tobacco, Firearms and Explosives agent contacted by KVOA said his agency is already beginning to monitor for bulk ammunition traffickings if the Sinaloa Cartel is pushed out of Arizona and Sonora following Chapo Guzmán's arrest. "If you start seeing violence in Juárez again, in Hermosillo, especially in Tijuana, you'll know the Mexican government didn't allow for a transition to be put in place before they took him down," the agent said.

"I recognize the work of the security institutions of the Mexican state to make the arrest of Joaquín Guzmán Loera in Mazatlán," the Twitter account stated.

In a statement out of Washington, D.C., Attorney General Eric Holder said, "Today's apprehension of Joaquín "Chapo" Guzmán Loera is a landmark achievement."

Agents with the DEA and the U.S. Marshal's Office helped Mexico make the arrest.

The arrest followed a major operation in the city of Culiacán, Sinaloa over the past week. Mexican Marines and federal investigators systematically arrested bodyguards tied to Guzmán's cartel associate, Ismaél El Mayo Zambada. On February 13, Joel Enrique "El 19" Sandoval Romero was arrested. He was a close bodyguard to Zambada. The next day, Jesús "El 20" Peña, long considered one of Zambada's strongarms, was also arrested. Last Friday, federal police and marines raided the home of Guzmán's ex-wife, Griselda Peréz Lopéz.

Rumors of major movements against the Sinaloa Cartel go back to last December when a major enforcer Jesús Gregorio "El R5" Villanueva was murdered in Hermosillo, Sonora. Villanueva controlled the border city of Agua Prieta for the Sinaloa Cartel. That was followed by the killing – and subsequent disappearance – of Gonzalo "El Macho Prieto" Inzunza Inzunza, a strongarm for the powerful cartel who controlled most of northern Sonora. He died after federal police raided a resort in Rocky Point. Inzunza had worked for the Sinaloa Cartel since the 2000 George Bush presidency.

Last spring, Guzmán's father-in-law, Ines Coronel Barreras, was also arrested in Agua Prieta.

Guzmán's arrest follows years of accusations that the government of Mexico was protecting the Sinaloa Cartel against the Zetas, the Beltrán Leyvas and the Juárez Cartel. Former president Felipe Calderón was criticized for years after seemingly only targeting those cartels opposed to Sinaloa.

Neither Mexico nor the United States has mentioned his extradition to the U.S. yet.

Steve Ralls, a Tucson criminal defense attorney who represented such Sinaloa Cartel figures as Sandra Avíla Beltrán, Miguel Caro Quintero, and Guzmán's younger brother, Arturo, said an extradition can take three to five years.

"The Mexican extradition process is very lengthy, time-consuming, complicated. I don't anticipate it's going to take any place any sooner unless Mr. Guzmán strikes a deal for some benefit to the U.S."

Ralls said he wasn't surprised by the arrest.

"The American law enforcement working with Mexican law enforcement was bound to arrest him sooner or later."